This is one of my first projects in JIPCAD, before I was very familiar with sweeps or (apparently) taking screenshots.
The blue outline on the left shows the intended path of the sweep, a cube with only one line connecting the top and bottom faces, and the right shows the actual sweep path. I was new at using B-splines when working on this project, and so struggled with understanding why the two weren't the same, as well as why my swept polygon was broken in several places and why half of my bowtie was black (meaning on the "inside" of the shape).
Still, it was an informative project that pushed me to design more intracite sweeps and later knots, and I was impressed at what I could come up with given very little experience or work in JIPCAD.